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Chat with a PDF

You do not need to read a whole PDF to understand it. Upload the file, ask a question in plain words, and the AI answers from the text inside it — a summary, an explanation, or the one fact you actually need. This guide shows you how to chat with a PDF on OpenChatGPT, what to ask, and where the limits are.

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How to chat with a PDF

It takes less than a minute, and there is no account to create. Open the chat and tap the attach button (📎) next to the microphone at the bottom of the screen. Choose your PDF file from your phone or computer — it appears as a small chip above the message box, with the file name and size. Then type your question and press Send. If you send the file with no question at all, the chat summarises it for you. The chat reads the text inside the PDF and answers from it, in the same conversation, so you can keep asking follow-up questions: "Explain that part more simply", "Give me an example", "What does it say about the deadline?" Each follow-up stays in the same chat, so the AI remembers which file you are talking about. When you are done, the file chip disappears and you can attach a different PDF. Your chats are stored only in your own browser, on your own device.

What to ask a PDF — worked examples

The best questions are specific. "Tell me about this" gets you a vague summary; a question with a shape gets you a useful answer. Here are four that work well, with the kind of file each one suits.

1. "Summarise this PDF in 10 bullet points." Best for: a long report, a research paper, a set of meeting notes, a government notice. You get the main points in a minute instead of reading twenty pages. If the summary is too long, say "Make it 5 bullet points" — or too short, say "Add the numbers and dates you left out." A good follow-up is "What is the single most important point in this document?" — it forces the chat to choose, and the choice tells you what the document is really about.

2. "Explain section 3 of this document in simple words, as if I am a complete beginner." Best for: a textbook chapter, a contract, a manual, a set of rules. The chat explains the part you point at, not the whole file. If a sentence is still unclear, quote it back: "What does this sentence mean: 'The lessee shall indemnify the lessor against all claims'?" Quoting the exact sentence gets you an exact explanation, and it stops the chat from guessing about a different part of the file.

3. "What does this file say about the refund policy? Quote the exact part." Best for: terms and conditions, a contract, a policy document, a user manual. Asking for a quote matters here: when the chat has to quote, it stays close to the text instead of summarising from memory. Read the quote against the PDF yourself before you act on it — especially for money, deadlines, and legal wording. If the chat says "the file does not mention this", believe that over a confident-sounding invented answer.

4. "Quiz me on this chapter: ask me one question at a time and tell me if I am right." Best for: study notes, a textbook chapter, a training manual. The chat turns the file into a practice test. Answer each question in the chat, and it tells you whether you are right and explains the answer when you are wrong. When you finish, ask "Which topics did I get wrong? Make 5 more questions on those topics." It is one of the most effective ways to revise, because you are recalling the material instead of re-reading it.

The limits, honestly

PDF chat works on text PDFs — files where the words are real text, like a document exported from Word or downloaded from a website. It has four hard limits. First, the file must be 10 MB or smaller. Second, only the first 20 pages are read. Third, only the first 12,000 characters of text are sent to the AI — roughly 2,000 words, or about four pages of normal text. If your question is about something on page 30 of a long report, the chat has not seen it and will say so; split the file or ask about the part it did read. Fourth, scanned PDFs do not work: if the PDF is just photos of pages, there is no text to read, and the chat will tell you it found nothing. For a scanned page, take a photo or a screenshot of the page and upload that as an image instead — the chat can read the image. Two more cautions: tables and numbers can be misread, so check any figure before you quote it, and the AI can invent details that sound convincing, so ask it to quote the text when the answer matters.

For students: textbooks, notes, past papers

Students get the most out of PDF chat, because so much study material arrives as a PDF. A textbook chapter becomes a summary and a quiz: upload the chapter, ask for a summary in your own words, then ask to be quizzed on it — one question at a time, with corrections. Lecture notes become explanations: "Explain the part about photosynthesis in this file, with a real-life example" turns a dense page into something you can actually picture. Past papers become practice: upload a past paper and ask "What topics appear most often in this paper?" and then "Make 5 practice questions in the same style as question 3." A research paper becomes a one-paragraph answer: "What is the main finding of this paper, in one paragraph, in simple words?" The pattern is always the same: the PDF holds the facts, and your question decides what you get out of them. One habit worth building: after the chat explains something, close the file and explain it back in your own words. If you can explain it without looking, you know it.

What happens to your PDF

The text of your PDF is extracted in your own browser, then sent to the AI provider as part of your chat message so the model can answer from it. The file itself is not uploaded to or stored on this site's server, and the extracted text is not kept anywhere except in your own browser's chat history — the same place your typed messages are kept. The AI provider receives the text only to generate your reply. Even so, do not upload files that contain passwords, bank details, ID numbers, medical records, or other sensitive information. If a document is private, ask yourself whether you need the AI's help with it at all — and if you do, remove the sensitive pages first. The privacy policy and the AI disclosure explain this in full.

Common mistakes

Ready to try it? Start chatting — tap the attach button, choose a PDF, and ask your first question. It is free, needs no account, and there is no daily limit on messages. For more ways to use the chat, see the guide on AI chat for students or how to use OpenChatGPT.

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